Introduction: The greatest threat that diagnosticians and physicians face today is from the multi drug resistant bacteria. The multidrug resistance associated with extended spectrum β lactamases (ESBL), Amp-C and metallo β lactamase (MBL) producers poses a considerable therapeutic challenge leading to treatment failure. So the present study was conducted to detect the occurrence of various β Lactamases in the clinical isolates.

Materials and Methods: We included a total of consecutive 206 isolates of Escherichia coli and Klebsiella pneumonia in our study, over a period of one year. Antibiotic susceptibility testing was performed in accordance with guidelines by Clinical and Laboratory Standards institute (CLSI). ESBL production was confirmed by using the double disc diffusion test recommended by CLSI. AmpC disc test was performed for confirmation of AmpC production and MBL producers were detected using EDTA disc potentiation test.

Result: Of the total 206 isolates, 46 (22.33%) were found to be pure ESBL producers, 64 (31.06) were AmpC producers out of which only one isolate produced pure AmpC. MBL production was confirmed in 11 (5.33%) isolates. The significant finding of this study was the co production of ESBL and AmpC which was detected in 53 (25.72%), taking the total number of ESBL producers to 99 (48.05%). AmpC and MBL were co produced by 10 (4.85%) isolates. 

Conclusion: Routine laboratory detection of multiple beta lactamases has become the need of the hour and is recommended, since the occurrence and co-existence of beta lactamases in Gram negative bacilli is on the rise.

Keywords: Extended Spectrum Beta Lactamases (ESBL); AmpC Beta Lactamase; Metallo Beta Lactamase (MBL); Co-Producers.